Nicholas conrad heissler



(HOMO-(151.) I 2 Sheets-Sheet 1.

N. 0. HEISSLER.

TELEPHONE SYSTEM.

N0.s51,5 97.- Patented 001;. 26, 1886.

JLLL

(No Model.) Y

- 2 SheetsSheet 2. N. U. HEISSLER.

TELEPHONE SYSTEM.

No. 351,591 Patented 001;. 26, 188 6.

UNITED STATES PATENT Erica.

TELEPHONE SYSTEM.

SPECIFICATION forming part of Letters Patent 180351597, dated Qctoloer26, 1886.

Application filed July 23, 1886. Serial No. 208,834. (No model.)

' T aZZ whom, it may concern:

Be it known that I, NICHOLAS CONRAD HEISSLER, a subject of the Czar ofRussia, residing at St. Petersburg, in the Empire of Russia, haveinvented a certain new and useful Improvement in Telephone Systems, ofwhich the following is a specification.

The object I have in view is to produce telephonic apparatus which willenable one line to be used for the instruments of twosubscribers, andwill permit the independent use of thewire by each'subscriber withoutdisturbing the other, andwithout the liability of being interfered withor overheard by the other subscriber; and more especially my object isto do this by means which will enable the employvment .of the ordinarytelephone-instruments and call apparatus in connection therewith, andwill require no radical departure from the present methods of conductingtelephone-exchanges, and which, further, will be simple in constructionand not liable to get out of order or adjustment, and will be entirelycertain in action and simple in its manipulation. The conditionsof'independent use of the line re quire that the central oflice shouldbe able to call up either subscriber, or either subscriber call up thecentral office, without disturbing the other subscriber, and that whenthe instruments of one subscriber are in position for talking the otherwill not be able to interfere with the line in any way, and cannotoverhear the conversation; also, that. the two subscribers may be put,into communication with each other.

The advantages arising from a practical apparatus accomplishingeffectively the object stated are, that the cost of construction overthe use of a separate linewire for each subscriber is greatly reduced,while most of the benefits of the separate line for each telephone areretained. y

In the accompanying drawings, forming a part hereof, Figure 1 is a view,partly in diagram, rep resenting a central office and two telephonesconnected with the same line, the transmitters at outlying telephonesbeing omitted for simplicity; Fig. 2, a view illustrating thecentral-office device for operating the polarized switch for makingconnections with either of the two outlying telephones; Fig. 3, a Viewlike Fig. l of a modified arrangement of circonnected with telephone T.

cuits, showing the position of hand-switch to connect the two outlyingtelephones together, and showing also a different form of theswitching-key at central oflice; and Fig. 4, a side elevation of mainmagnet of the automatic switch.

The automatic switch, which is the most prominent feature of myapparatus, is con s'tructed as follows: M M are the two bobbins of adifferentially-wound electro-magnet, with inner circuit, in, composed offine wire and outer circuit, w, of coarse wire. The permanent magnet NS, extending behind the bobbins M M, as shown. polarizes the cores ofthe electro-magnet M M by contact and its armature n by induction, themagnet N S approaching very close to but not touching the armature. Anextension of the armature n has two contact-screws, c d, both of them inelectrical connection with the armature. Upon an insulated block, It,fastened between the bobbins M M, are two springs, to and b, insulatedfrom each other, and limited in their motion by the two insulated screws0 and d, which are in electrical connection with each other. By means ofthe screws 0 c d d the springs a and b are regulated, so that one ofthem will be in contact with the armature a by either 0 or (I, while theother will be in contact with either of the screws 0 or (1'. Forinstance, in the drawings spring a is shown in contact with armaturen byscrew 0, and is separated from screw 0, and spring I) is shown incontact with screw d, and is separated from the screw (1, whereas ifarmature n were tilted the opposite would be the case. Springa isconnected to telephone T, and spring b is The line from centraloffice'passes by binding-post L to and through outer circuit, 10, ofelectro-magnet M M, and terminates in contact with armature a.

As will be presently explained in detail, if spring a is in contact witharmature n by screw 0, then the telephone T is in direct connection withcentral office, and telephone T is disconnected from armature n at screw01, and consequently disconnected from the central office, while ifarmature n were tilted the reverse wouldbe the case. The armaturen tiltsor oscillates like all polarized relays and elec tro-magnets-i. 6., ifacurrent of polarity circulates through the coil the armature will bg;

attracted to one pole of the electro-inagnet, while aeurrent of polaritywill cause it tobe attracted to the other pole.

The auxiliary electi'oniagnet B is employed to short-circuit the inneror tine-wire circuit, to, of electro-niagnet M M by means of armature eand contact-screwy, and to open this short circuit automatically whenany current passes through the coil B, thus allowing the current tocirculate through the fine coils w of electroniagnrt M M to operate thearmature n.

Manual revei'singswitch C is only used when the two telephone-stations Aand B desire to communicate with each other, in which case moving thehandle to the left places them in connection with each other and withthe central oifice, enabling the central oflice to control thecommunication andto receive the disconnect signal when conversation isfinished.

The circuits are as follows: The main line M L, connected in centraloflice through the ordinary signatdrop or other annnnciator to earth,passes thence to telephone-station, going immediately to theautomaticcommutator at binding-post L,to and through outer or coarsewirecoils, w, of polarized electro-niagnet M l\I,terniinating in electricalconnection with armature n, to which are attached the two contact-screws cand d. From springaa wire passes via binding-post A totelephone-hook H in telephone '1", thence by spring 8 through inagnetocall general or G to binding-post B, to contact-spring 5 7 (i, tobinding-post L, to telephone-hook H in telephone T, thence to earth atplate P. Froin springb line passes by contacts 2, S, and l tobinding-post L, to inagneto-call generator G at telephone T, thence toearth by telephone-hook H and plate P. Froin earth at P a line passes tobinding-post E, thence by contacts 3,9,and 4. to binding-post T, thenceto and through telephone T to spring 8. A branch wire lroin P passes byspring .9, insulated contact-piece 10 on switch-lever H, and spring stobinding-post E, thencethrhugh coil ot'electro-niagnet B, branching atz,where the two ends of inner line-wire coil on electromagnet M M,including contact-screwf and armature e, are connected. From a point, 3of this iinewire circuit a connection is made with the twocontact-screws c and d, as shown in Fig. 1.

Operation.

Case I Central office wishes to call telephone T. from the earth-stripand placed in the hole iiitersecting the line M L and the cross-strip,to which the battery M B and push-buttons P B are connected. Theoperator then presses the button l several times, which connects zinc ofbattery M B to earth and copper to lineM L, causing a lcurrent to flowthrough line ML to binding-post L, through the outer or coarsewire coilof eleetro-inagnet M M to armature it. From this point the current goesto earth either via spring a, bindingpost A to telephone T, fork H S,generator G, binding-post Plug in switch-board is removed B, contacts 56 7, binding-post L to telephone T, spring .5 to earth direct at P, orvia spring 11, contacts 1 2 8, binding post L" to telephone T, generatorG, spring 5- to earth at l The reason for one or the other of theseroutes be ing followed is, that the armature n remains in the positionin which it was when last used. Therefore if telephone T had the lastconnection the current would follow the first-mentioned route, while iftelephone T had the last connection the route would be the lastdescribed. In the present case, with armature n as shown in thedrawings, the current reaches earth by thefirst route. in circulatingthrough the outer coil of electro-niagnet M M the current causes thearmature n to be tilted in the direction shown in the drawings.Naturally, if the armature is already in that position the currents donot affect it. The central office now removes theplug from theintersection of line and cross-strip with battery to the stripordinarily used for signaling. and sends alternate currents, as usual,either from a magnetogenerator or a pOlechanger, which pass through thecoils M M, thence by spring a,with its connections,to and through bellof generator G, causing it to ring, thence on to telephone T at spring 8and to earth at P without passing through hell of generator G. Armaturen is mounted on pivots, and is very sensitive, and it no provision weremade itwould vibrate in response to the alternating currents passingthrough the coarse wire 10 of coils M M, sending one half of the signalto T and the other halt to T, and probably coming to rest in connectionwith telephone T,if the last current should be of the polarity affectingthe armature in that direction. This does not occur when direct currentsare sent, but only when intermittent induced currents pass through thecoarse-wire coils, for although the induction occurs, yet the directcurrents are unavoidably prolonged sulii'cient to attract the armaturea. To prevent these results the resistance of tine-wire coils w on M Mis so proportioned to that of the coarse-wire coils 10 that the currentsof opposite polarity produced in the former by induction from the latterneutralize the effect of the currents in the coarse coils upon thearmature n; hence no change in theposition ol'the armature occnrs,ai1dthe signals pass through and afl'ectgeuei'atorG only. Thisis a featureof prime importance, enabling alternating signaling-cnrrcnts to passdirectly through the polarized switch without vibrating its arniatnreand without disturbing the connections produced byit.TelephoneTresponds, as usual, by reinovinghis receiver from hook 11.This automatically cuts out his bell and throws his telephone into thecircuit, and also breaks the circuit of telephone T by re moving thecontact 10 from springs s .9", thereby preventing telephone T fromringing or hearing during the communication, or as long as telephone Tis off the hook H.

Case II: Central office desires to communicate with telephone T.Operation in central,

oflice is the same as before, except that button is used, putting copperto earth and zinc to line, and causing a curreutto pass through thecoarse wire of coils M M. Armature n is thereby afl'ected, so that theend formerly attracted is now repelled by cores of M M. Screw '01 nowmakes contact with and removes spring b from its contact with screw d,and severs the connection between screw 0 and spring at, al lowing thelatter to restin contact with screw 0'. Central office now signals asbefore, when the currents pass through coarse-wire coils of M M, andthen by spring b and its connections to and through generator G',(thebell of which they cause to ring,) and to. earth at P. N o movement ofarmature it occurs, because, as before stated, the efl'ect of thecurrents passing through the coarse coils and the currents they inducein the fine-wire coils of M M are balancetl. Telephone T responds byremoving the receiver from hook H, which, while it performs theswitchingnecessary for talking, also breaks the line of telephone T by severingthe connection between spring 8 and hook H, thereby preventing thelatter from ringing or interrupting or hearing the communication.

Jase 111: Telephone Tdesires'to communicate with central office. Whenthe armature it happens to'be in the position shown in drawings t'. 6,,in contact with spring athe currents from generator G go direct tocentral office without affecting any part of the automaticcommutator.When thearmaturenhappens to be in contact with spring b,while spring ais separated from it, but in contact by screw 0 with the fine-wire coilsof M M and the auxiliary lectro-magnet B, then thcalternating currentsfrom generator G must cause the armature n to reverse, thus placingspring a in contact with the armature n, and at the same time to signalthe central office. When gen erator Gis put in motion by turning thecrank in usual manner, the alternating currents then generated startfrom earth at P to hook H, out by spring 8 binding-post L, contacts 6 75, bindingpost B, generator G, spring 8 hook H, to binding-post A,spring a, con tact-screw c, to tap connection 3 From this point thecurrents have two paths to tollowone, of high resistance, through thefinewi re coils w, to tap z, the other, of very low relative resistance,to screw f, armature e, to tap z, and from this point through the coil Bto binding-post E, to spring 8', contact 10, spring 8, to earth at P.When the currents arrive at y,almost the entire amount passes by screwf, armature e, and tap 2 through the coils B, on account of this beingby far the shorter path, and the small amount of current which passesthrough the tine-wire coils M M is too weak to affect the armaturen. Thecurrents in passing through electromagnet B cause armatureeto'beattracted, thus opening the circuit at screw f, and causing the entirecurrent to take the other path through the tine-wire coils of M M, asbefore described. Should the first current not be in the requireddirection, it will passing by contacts 1 8 2 to spring b.

only draw the armature a more strongly to the side it is on; but thenext current,which must be in ,the required direction, will cause thearmature a to reverse its position, thus putting the spring a inconnection with armature n, and therefore in direct connection withcentral office, while the connections from screw 0, including auxiliaryelectro-magnet B and finewire coils of M M, are thrown out of circuit,and the balance of the currents pass to central office and are employedin giving the signal there. Armature e returns to its position incontact with screwf as soon as the currents cease to traverse the coilB.

Case IV: Telephone T wishes to communicate with central office.Generator G, with earth at P, produces alternating currents, which flowinto automatic commutator at L As in Case lII, should the armature italready be in proper position, the signal goes direct to central office;but should it be in the position shown in drawings, then the sameact-ion occurs as described in Case IIIviz., the currents pass throughcoil B,breaking the circuit at f, and cause the currents to traversefinewire coils w of M M, throwing the armature n to other side andplacing spring I) in contact with armature n at screw (1, the signalthen passing on to central of'fice.

Case V: Telephone T wishes to communicate with telephone T. Centraloffice is signaled, as in Case III. and notified of the desire,whereuponmanual switch C is turned by subscriber at T, at or near whose telephonethe automa ic switching apparatus is located, to the position shown inFig. 3, connecting 4 and'5 with 1, and signal given by generator G orfrom central office, ringing both bells of generators G G. .Circuit isthen from earth in central office to binding-post L, through coarse-wirecoils of M M to armature n, spring a to binding-post A, to hook H, tospring 8 for signal, or s for speaking, to contacts 4 and 5 on 9, out byopposite side of 9 to l. to bind ing-post L", bell and telephone at T,by spring '8 or s to hook H, to earth at P.

Case VI: Telephone T desires to communicate with telephone T. Centralofiice IS signaled, as in Case IV, and notified of the wish. Centraloffice then signals to telephone T, and

'instructs him to move manual switch to left and speak with T, whereuponthe circuit is same as in Case V.

IIC

.W-hen conversation is finished in Cases V tance from each other, but insame direction from central office, would be placed on one wire. Cost ofa second wire between the two would then be considerable, and can bedispensed with by omitting the connections of binding-posts B and L andconnecting the generator G with wire to post T, and also bydisconnecting screw 0 and using it only as an insulated limiting-stop,so as to prevent T from interrupting the conversations of T. Thisarrangement ofcircuitsis shown in Fig. 8.

\Vith the twowire system it is immaterial to which side the armature itremains after being used; but if using only one wire between stationsthe central ot'fice must always place armature n in connection withspring a by means of a current of proper polarity after eachcommunication. Should this be forgotten, the spring a would often beleft insulated at c, leaving line of telephone T open at that point,which would lead to much dissatisfaction.

In order to remove any chance of mistake by the operatorin centralot'fiee, and to render each station independent of the other, thetwowire system should be used where the distances are not too great.

The device at central oflice for throwing a current from M B onto lineof one polarity or the other to set automatic switch may be of anysuitable character. The double pushbutton shown in Fig. 2 may be used,each pushbntton controllingtwo sets of contacts, as clearly shown; or acircuit-reversing switch and a key may be employed, as shown in Fig. 3.The central-office telephone with magnetocall is shown at O T.

It is evident that the automatic switch is capable of use in anyelectrical system where the functions it is capable of performing willprove useful, as in telegraphy, messenger, firealarm, and burglar-alarmservice, and in elec tric lighting.

What I claim is 1. In a telephone system, the combination, with a singlemai u 1i ne, of two sets oftelephoneinstruments and a polarizedautomatic switch for connecting either telephone with the centralot'fice, substantially as set forth.

2. In a telephone system, the combination, with a single main line, oftwo sets oftelephoneinstruments, a polarized automatic switch forconnecting either telephone with the central otlice, magneto-generatorcalls, and a differentiating circuit neutralizing the alternating orintermittent call -currcnts at the automatic switch after the switch isset, substantially as set forth.

3. In a telephone system, the combination, with a single main line, oftwo sets of telephone instruments, a polarized automatic switch forconnecting either telephone with the central office, magneto generatorcalls, a differentiating circuit neutralizing the alternating orintermittent call-cnrrents at the automatic switch after the switch isset, and a magnet opening the neutralizing-cireuit to permit the settingof the switch by the alternating or intermittent call-currents,substantially as set forth.

4. A polarized switch provided with two sets of coils, one of which isin line and the other in a closed local circuit, such coils beingproportioned so that alternating or intermittent currents in theline-coils will be neutralized in their magnetizing effect by theinduced currents in the closed local circuit, substantially as setforth.

5. A polarized switch provided with two sets of coils, one of which isin line and the other in a closed local circuit, such coils beingproportioned so that alternating or intermittent currents in thelinecoils will be neutralized in their magnetizing effect by the inducedcurrents in the closed local circuit, in combination with a magnetcontrolling said local circuit and opening it to permit alternating orintermittent currents to act on the polarized switch, substantially asset forth.

6. In a telephone system, the combination, with a single line fromcentral otlice, of a polarized switch having one set of coils in saidline, two contacts made alternately by the armature of said switch, twotelephones connected, respectively, with said contacts, whereby aprolonged current of positive or negative polarity from the centraloffice willshift said switch to connect one or the other of thetelephones with the central office, and a local neutralizing-circuit atsaid switch to permit alternating or intermittent call-currents to besent through it without disturbing its position,substantially as setforth.

7. In a telephone system. the combination, with a single line fromcentral oliice, of a polarized switclrmagnet having one set of coils insaid line, two springs alternately in contact with the armature of saidswitch-magnet, two stationary contacts made by said springs when notthrown off by the armaturc,two telephones connected with said springs, anormally-closed neutralizing-circuit at said switch, connected with oneor both of said stationary contacts, and a magnet for opening saidneutralizingcircuit and throwing it into circuit with a magnetotelephone-call, whereby the switch will be automatically set by thecall'currents, and will then permit such currents to pass withoutdisturbing it further, substantially as set forth.

8. In a telephone system, the combination, with a central office, of asingle line therefrom, two telephones connected therewith, and anautomatic polarized directing-switch located at one of such telephonesfor connecting the telephones separately with the central office,substantially as set forth.

9. In a telephone system, the combination, with a central ofiice, of asingle line therefrom, two telephones connected therewith, an automaticpolarized directing-switch located at one of such telephones forconnecting the telephones separately with the central ot'fice, andconnections from the automatic switch through the hook of one or of eachtelephone, for preventing interference by one telephone when the otheris in use, substantially as set forth.

10. In a telephone system, the combination, with a central ofiice, of asingleline therefrom, two telephones connected therewith, an auto maficpolarized directing-switch located at one of such telephones forconnecting the telephones separately with the central office, and a handswitch at the same telephone for connecting said two telephones forcommunication between them, substantially as set forth.

11. In atelephone system, the combination,

with the central ofiice and the single line therefrom, of thedifferentially wound polarized switch-magnet M, the local magnet B,handswitch 0, telephone sets T T, and the connecting circuits,constructed and arranged for operation substantially as set forth.

This specification signed and witnessed this 11th day of June, 1886.

NICHOLAS CONRAD HEISSLER.

Witnesses:

EMIL AHLEFELDT LAURVIGEN, ERNST DELACROIX.

